The invention relates to a building element consisting of two parallel wire grid mats, of straight web wires which hold the wire grid mats at a predetermined distance apart and are joined at each end to the two wire grid mats, and of an insulating body which is arranged between the wire grid mats and through which the web wires pass.
From AT-PS 372 886 a method and an apparatus for producing a building element of this kind are known. For this purpose two lengths of wire grid are first brought into a parallel position at a distance apart corresponding to the desired thickness of the grid body which is to be produced. An insulating body is inserted into the gap between the lengths of wire grid, at a distance from each of the lengths of wire grid. Web wires are passed through one of the two lengths of wire grid into the gap between the latter and the insulating body, in such a manner that each web wire comes to lie close to a grid wire of each of the two lengths of wire grid, whereupon the web wires are welded to the grid wires of the lengths of wire grid. Finally, building elements of appropriate length are separated off from the grid body produced in this manner.
From U.S. Pat. No. 3,305,991 a building element is known which consists of a three-dimensional grid body in which a one-piece insulating body is formed in situ by foaming. The grid body comprises two wire grid mats which are arranged at a distance from one another and which are joined by means of zigzag web wires. On the building site the building element is provided with a coating of concrete or mortar on each of its two cover surfaces. It is here a disadvantage that because of the complicated production process a modification of the shape and dimensions of the building element, particularly for the purpose of adaptation to different static requirements, is possible only with difficulty, and that only materials which can be foamed in situ can be used as material for the insulating body. It is also a disadvantage that the web wires can be connected at their wave crests to the grid wires only at one point in each case.
From U.S. Pat. No. 4,104,842 a building element is known whose three-dimensional grid body likewise comprises two wire grid mats arranged at a distance from one another, together with web wires of a zigzag configuration which join together the wire grid mats. On the inner side of at least one wire grid mat, spaced apart from the latter, a cover layer of building paper is applied to serve as limiting layer for the concrete shell subsequently to be applied. If two cover layers are used, a cavity which can subsequently be filled with material is formed in the interior of the building element. Here again a disadvantage is the complicated production process, which makes it difficult to modify the shape and dimensions of the building element, and also the fact that the materials for the insulating body are restricted to substances which must be pourable or flowable in order to be able to fill the cavity which is formed in the building element and through which the zigzag web wires pass. It is in addition a disadvantage that the web wires are connected at their wave crests to the grid wires only at one point in each case.
The problem underlying the invention is that of providing a building element of the type indicated in the preamble above, which can be produced in a simple manner and can quickly be adapted to various static requirements. The building element should at the same time permit the selection of different materials for the insulating body and facilitate the application of the concrete layer at the site where the building element is to be used. The building element according to the invention is distinguished in that at least one of the wire grid mats is in the form of a grid reinforcement mat which possesses a minimum strength of the weld nodes which complies with the static requirements applicable to the building element, corresponding mechanical strength of the grid mat wires and also corresponding diameters and mutual spacings of the grid mat wires, in that the web wires are arranged in predetermined directions relative to the wire grid mats, and in that the insulating body is held at a predetermined distance from each of the wire grid mats.
In comparison with the known building elements having zigzag web wires and only one weld point in the region of the wave crest, the building element according to the invention has the advantage that the web wires are in the form of individual wires and therefore two weld points exist in the region of the connection to the grid mat wires, so that static safety is practically doubled.
In the building element according to the invention the web wires are preferably arranged in trelliswork fashion between the wires of the wire grid mats and are inclined alternately in opposite directions. As an alternative, the web wires can be arranged, between the wires of the wire grid mats, in rows in which the web wires are inclined in the same direction, the directional sense changing from row to row. According to another variant of the invention the web wires may extend at right angles to the wire grid mats, and the insulating body may be additionally fastenable in position relative to the wire grid mats by means of a plurality of spacers supported on the wires of the wire grid mats.
In a preferred embodiment of the invention the grid body formed from the wire grid mats and the web wires is reinforced, at least at two opposite edges, by edge web wires which preferably extend at right angles to the wire grid mats and are welded to the edge wires of the grid mats. At the edge of the wire grid mats the grid mat wires preferably end in this case flush with the respective edge wires of the grid mats.
Within the scope of the invention the insulating body preferably consists of a dimensionally stable material, which expediently is an acoustic and thermal insulator.
According to the invention, however, two separating layers, which are arranged at a predetermined distance from the wire grid mats, are fastened by the web wires and/or the spacers and enclose a gap of predetermined width, may also be provided, while in order to form a central insulating layer the gap may preferably be filled with heapable, pourable or flowable materials which preferably are acoustic and thermal insulators.
For the practical use of the building element as a wall or ceiling element it is particularly advantageous for at least one wire grid mat to project laterally beyond the insulating body or the central insulating layer at at least one side surface of the insulating body or of the central insulating layer. In this case there may be applied to the outer wire grid mat which is intended to form the outer side of the building element an outer shell of concrete, which adjoins the insulating body or the separating layer adjoining the outer wire grid mat and surrounds the outer wire grid mat and which, together with the latter, forms the bearing component of the building element.
According to another feature of the invention there is applied to the inner wire grid mat which is intended to form the inner side of the building element an inner shell, which adjoins the insulating body or the separating layer adjoining the inner wire grid mat and surrounds the inner wire grid mat and which, together with the latter, forms the bearing component of the building element.